Exposure to high levels of indoor allergens (e.g., from cockroaches and rodents) is thought to be one factor among the multiple causes of the disproportionate burden of asthma in disadvantaged urban neighborhoods of New York City. This study is testing an intervention to reduce exposure to indoor allergens among asthmatic children in NYC, and examining the correlation of such reductions with inprovements in allergic sensitization and/or asthma symptoms. We are recruiting 70 asthmatic children who are allergic to cockroaches and live in apartments with reported cockroach infestation. Each apartment undergoes a baseline inspection and environmental assessment, including dust sample collection of indoor allergens. Individual sensitization to allergens is assessed in the asthmatic children via skin prick test and serum IgE. Asthma symptoms are assessed using standardized questionnaires. All homes will undergo a comprehensive pest control intervention; however, half of the homes will undergo intervention at the beginning of the study, and the other half will undergo intervention after eight months. Selection for these two groups will be done randomly. The intervention consists of the following: sealing all cracks and crevices in the structural envelope of the apartment, application of low toxicity pesticides, thorough cleaning of surfaces, elimination of food and water sources, and education regarding the maintenance of a pest-free environment. As part of sub-study in 20 homes, we are collecting indooor air samples from the bedroom and kitchen before and after the intervention. Follow-up assesment of allergen exposures, immunologic sensitization, and asthma symptoms will be made at 4 and 8 months following baseline in the group that undergoes intervention at the beginning of the study; and at 4,7,12 and 16 months following baseline in the group that undergoes intervention after 8 months.